1. Technical Field
The present disclosure relates to paper machinery, and more particularly relates to transfer systems for changing the paper machinery between interchangeably manufacturing wet crepe paper and dry crepe paper on the same paper machine.
2. Related Art
Paper machines adapted for production of rolls of wet and dry crepe paper in the range of, for example, 100 to 300 inches, are large pieces of equipment sometimes more than 100 yards in length and equipped with a large number of rolls. Paper production using this type of paper machinery begins with injecting a paper stock having a consistency of less than 1% paper fiber and at least 99% water into a forming section. In the forming section, the paper stock is supplied to a headbox and passes through a controlling orifice, which feeds the paper stock onto a forming zone. There are many different types of formers for use in the forming zone; among them are the fourdrinier, twin wire, hybrid twin wire, and crescent formers. After the web leaves the forming zone, it is pressed between a pressure roll(s) and a Yankee dryer cylinder. This process transfers water from the paper web and forces the paper fibers in the paper web closer together and starts the transfer of the paper web to the Yankee dryer cylinder. The Yankee dryer heats the paper web and a dryer hood of the Yankee dryer force heated air onto the paper web to remove water by evaporation. An adhesive and release agent is applied to the Yankee dryer to permit transfer and later release of the paper web relative to the Yankee dryer.
The paper web is creped by a creping doctor as it is removed from the Yankee dryer. When a dry crepe paper is being produced, the dry crepe paper web is immediately wound on a reel after being removed from the Yankee dryer. When a wet crepe paper is being produced, the wet crepe paper web after being removed from the Yankee dryer is transferred into a dryer section consisting of dryer fabric(s) and multiple steam dryer cylinders. In some wet crepe machines, the dryer section consists of several steam dryer cylinders. The paper web winds its way over and under the cylinders while being pressed against or held by dryer fabrics, felts or other carrier webbing. While in contact with each dryer cylinder or dryer fabric(s), the paper web absorbs heat. As the paper web travels through the dryer section, evaporation in the paper web occurs to dry the paper web to its final moisture content. A hood positioned over the dyer section removes moisture laden air without applying heated air on the paper web.
Because of the size and complexity of paper machinery, a substantial money and space investment is required to operate a paper machinery. Different paper machinery is usually required to make dry crepe tissue/towel paper versus wet crepe tissue/towel paper. The high capital costs and space requirements necessary for operating two separate sets of paper machinery for dry and wet crepe paper have resulted in the development of swing paper machine that can produce both dry and wet tissue/towel paper products. This type of multi-product machinery requires changing of at least some features of the machinery when changing (swinging) between production runs of wet crepe and dry crepe tissue/towel paper. The process of changing the paper machine between wet and dry crepe production setting is typically very time and labor intensive. The wet and dry crepe change process usually requires movement of large rollers and reels that require large lifting equipment and substantial care and attention. The changing process from dry to wet crepe paper processing also requires warming up the after dryers in the dryer section, which can result in additional down time. As expected, any down time for the paper machinery has a substantial associated cost related to decreased production.